Translaminar interspinous stabilization system

ABSTRACT

A translaminar, interspinous stabilization system is provided. The system may comprise an implantable device for placement between two adjacent vertebrae. The device may comprise an inferior section, a superior section, and a flexible midsection extending therebetween and configured to seat against the lamina between the adjacent vertebrae. A pair of lateral plates may extend from at least one of the inferior section and superior section for engaging a laminar surface of one of the vertebra. Each of the lateral plates includes an aperture for receiving a bone screw therethrough. Also provided is a bone screw for placement through at least one lateral plate for securing the device to the laminar surface of one of the vertebra.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.61/439,918 filed Feb. 6, 2011, and entitled “Translaminar InterspinousStabilization System”, the contents of which are incorporated herein byreference in their entirety.

FIELD

The present disclosure relates to devices and methods for treating spineinstability, including translaminar interspinous stabilization systemsand methods of using such systems for segmental stabilization ofadjacent vertebrae.

BACKGROUND

Spinal instability is often attributed to undesirable excessive motionbetween vertebrae and can cause significant pain and morbidity. Theinstability may result from a number of causes, including abnormalitiesof the vertebrae, the intervertebral discs, the facet joints, andconnective tissue around the spine. These abnormalities may arise fromdiseases, disorders or defects of the spine from trauma or bonedegradation, such as osteoarthritis, or degenerative disc disease. Whenthe spine becomes unstable, the vertebral column becomes misaligned andmay produce micromotion between adjacent vertebrae. Vertebralmisalignment and micromotion may result in wear to the vertebral bonesurfaces and ultimately generate severe pain. These conditions are oftenchronic and create progressive problems for the sufferer.

Known treatments for spinal instability can include long-term medicalmanagement or surgery. Medical management is generally directed atcontrolling the symptoms, such as pain reduction, rather than correctingthe underlying problem. For some patients, this may require chronic useof pain medications, which may alter patient mental state or cause othernegative side effects. Surgical treatment typically includesdecompression procedures to restore normal disc height, realign thecolumn, and alleviate the pain.

Recently, a variety of interspinous stabilization devices have becomeavailable. These devices are typically implanted between the spinousprocesses of two or more adjacent vertebrae. By stabilizing the spinousprocesses in this way, significant stress may be taken off theintervertebral discs to prevent disease progression or to improveconditions such as spinal stenosis. In addition, vertebral motion may becontrolled without severely altering the anatomy of the spine.

These devices, along with other interspinous stabilization systems, canbe secured between adjacent spinous processes using a number ofdifferent mechanisms. For example, such devices can include sharp barbsor other surface projections that engage the bony surface of a spinousprocess. In addition, flexible ligaments or sutures can be placed aroundthe implants and adjacent bone. In some cases, the devices may berigidly attached to the spinous process using a bone screw or othersuitable bone anchor to prevent the interspinous device from migratingor slipping out of position.

It may be desirable in some situations, such as where the spinousprocess is damaged, weakened, brittle or insufficient in size to serveas a bearing surface, to provide an interspinous stabilization devicethat can be anchored translaminarly. It is further desirable to providean interspinous stabilization system that can be configured to provideeither dynamic or rigid stability to the affected vertebral segment ofthe spinal column. For instance, it would be desirable to provide such asystem whereby the dynamic stability allows for controlled motion of theadjacent vertebrae being affected. It would be even more desirable toprovide the same system having the ability to allow for rigid,fusion-promoting securement if so desired or needed. Further still, itwould be desirable to provide a system that can provide the option ofeither dynamic or rigid stability at different levels of the vertebralsegment, while also allowing for multi-level vertebral stabilization.

SUMMARY

The present disclosure describes translaminar interspinous stabilizationsystems and methods of using these systems to treat spinal instabilityconditions. The systems may include an interspinous, interlaminarstabilization device configured for interlaminar placement between thespinous processes of adjacent vertebrae and secured to the lamina usingbone screws placed translaminarly. Also provided are methods for usingsuch systems.

One aspect of the disclosure relates to an implantable translaminar,interspinous stabilization system. The system may comprise animplantable device for placement between two adjacent vertebrae. Thedevice may comprise an inferior section, a superior section, and aflexible midsection extending therebetween. The device is configured toseat against the lamina between the adjacent vertebrae. A pair oflateral plates may extend from the inferior section and superior sectionfor engaging a laminar surface of one of the vertebra. Each of thelateral plates includes an aperture for receiving a bone fastenertherethrough. The system may also comprise a first bone fastener forplacement through one of the pair of lateral plates and a second bonefastener for placement through another one of the pair of lateral platesfor securing the device to the laminar surface of the one of thevertebra.

A second aspect of the present disclosure relates to an implantableinterspinous, interlaminar stabilization system. The system can comprisean implantable device for placement between two adjacent vertebrae. Thedevice may comprise an inferior section, a superior section, and aflexible midsection extending therebetween and configured to seatagainst the lamina of the vertebrae, and a pair of lateral plates forengaging a laminar surface of one of the vertebra. Each of the lateralplates may include an aperture for receiving a bone fastener. At leastone screw may be provided for placement through at least one lateralplate for securing the device to the laminar surface of one of thevertebra.

A third aspect of the present disclosure relates to a method ofsegmental stabilization of a spine. The method may comprise selecting avertebral level to be treated and then positioning an implantable devicebetween two spinous processes of two vertebrae of the selected vertebrallevel. The implantable device may comprise an inferior section, asuperior section, and a flexible midsection extending therebetweenconfigured to seat against the lamina between the adjacent vertebrae.The implant may further include a pair of lateral plates extending fromone of the inferior or superior sections, each of the lateral platesincluding an aperture for receiving a bone fastener therethrough andbeing configured to engage a laminar surface of one of the vertebrae.The implantable device can be secured by placing a bone fastener throughone of the pair of lateral plates, securing the device to the laminarsurface of one of the vertebra.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate several embodiments of thedisclosure and together with the description, serve to explain theprinciples of the disclosure.

FIG. 1 illustrates a perspective view of an interspinous, interlaminarvertebral stabilization device of the prior art.

FIG. 2 illustrates a side view of the prior art device of FIG. 1 insitu.

FIG. 3 illustrates a front perspective view of a translaminarinterspinous stabilization system of the present disclosure.

FIG. 4A illustrates a side view of the system of FIG. 3 in situ.

FIG. 4B illustrates a perspective view of the implanted system of FIG.4A.

FIG. 4C illustrates a top-down view of the implanted system of FIG. 4A.

FIG. 5 illustrates a front perspective view of another embodiment of atranslaminar interspinous stabilization system of the presentdisclosure.

FIG. 6A illustrates a perspective view of yet another embodiment of atranslaminar interspinous stabilization system of the presentdisclosure.

FIG. 6B illustrates a side view of the system of FIG. 6A.

FIG. 7A illustrates a front perspective view of the interspinousstabilization device and spacer of FIG. 6A.

FIG. 7B illustrates a side view of the interspinous stabilization deviceand spacer of FIG. 7A.

FIG. 7C illustrates a cross-sectional view of the interspinousstabilization device and spacer of FIG. 7A along lines 7C-7C.

FIG. 8 illustrates a perspective view of the implanted system of FIG. 7Ain situ.

FIG. 9A illustrates a top-down view of another embodiment of animplantable device of the present invention.

FIG. 9B illustrates a perspective view of the implantable device of FIG.9A.

FIG. 10A illustrates a top-down view of still another embodiment of animplantable device of the present invention.

FIG. 10B illustrates a perspective view of the implantable device ofFIG. 10A.

FIG. 11A illustrates a top-down view of still another embodiment of atranslaminar interspinous stabilization system of the presentdisclosure.

FIG. 11B illustrates a perspective view of the system of FIG. 11A.

FIG. 12 illustrates a perspective view of the implanted system of FIG.11A in situ.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory only,and are not restrictive of the disclosure, as claimed. Additionalfeatures of the disclosure will be set forth in part in the descriptionwhich follows or may be learned by practice of the disclosure. Thefeatures of the disclosure will be realized and attained by means of theelements and combinations particularly pointed out in the appendedclaims.

DESCRIPTION OF THE EMBODIMENTS

FIGS. 1 and 2 show a conventional implantable interlaminar-interspinousvertebral implant 1 of the kind disclosed, for example, in U.S. Pat. No.5,645,599 entitled “Interspinal Vertebral Implant” to Samani. Theimplant 1 may have a body 5, a central portion 5 a, and two branches 5 bin between. Brackets 6 extend from each of the two branches 5 b and formstirrups 7 for receiving spinous processes of adjacent vertebrae 3having articular processes 10 as shown. Holes 8 may be provided forreceiving bone screws 9 or spikes for securing the implant 1 to thevertebrae 3.

FIG. 3 shows a translaminar interspinous vertebral stabilization system20 of the present disclosure for stabilizing adjacent vertebrae. In oneembodiment, the system 20 comprises an implantable,interlaminar-interspinous device 22 configured for placement between thespinous processes of adjacent vertebrae. The system 20 can include oneor more fixation elements for securing the device 22 to the lamina ofthe adjacent vertebrae. In one embodiment, the fixation elements canrigidly fix the device with respect to the vertebrae, thereby limitingmovement at a selected vertebral level and promoting fusion at thatlevel. In another embodiment, the type of fixation elements may bevaried to provide varying degrees of fixation strength. The systemcould, for instance, allow for a combination of dynamic stabilization ofone vertebra and rigid stabilization of an adjacent vertebra atdifferent levels of the spine.

As shown, the implantable device 22 may be formed as a spacer body. Thedevice, or spacer body 22 may have various shapes and thicknesses, andcan be produced from a variety of different materials alone or incombination. In one embodiment, the spacer body 22 may include amidsection 30 extending between an inferior section 32 and a superiorsection 34, as shown in FIG. 3. When implanted in a patient, thesuperior section 34 is configured to contact a portion of a firstspinous process, while the inferior section 32 is configured to contacta portion of a second, adjacent spinous process. The spacer body 22 maybe configured to be flexible and/or bendable. For example, the spacerbody may comprise an extendable and/or compressible midsection 30. Themidsection 30 can act as a flexible hinge, allowing the superior section34 and inferior section 32 to move relative to each other, such as awayfrom or towards one another. In one embodiment, the midsection 30,inferior section 32, and superior section 34 may together form asubstantially U-shaped spacer body, as shown. The U-shaped spacer bodyenables the implantable device 22 to be positioned, or fitted,interlaminarly after implantation, thereby enhancing the stabilizationof the adjacent vertebrae.

To engage the spinous processes of adjacent vertebrae, the spacer body22 may be provided with a pair of lateral walls or brackets 36 thatextend from the inferior and superior sections 32, 34, as shown in FIG.3. Each of the pair of lateral walls 36 defines a stirrup 38 forreceiving a spinous process. As further shown in FIGS. 4A-4C, thelateral walls 36 are configured with plate-like wings or extensions thatextend beyond the spinous process and towards the lamina, and conform tothe contours of the patient's anatomy. These walls 36 or plates mayextend over a sizeable amount of lamina, as shown in FIGS. 4A and 4B.The walls 36 are shaped and sized to provide contact with the laminarsurface around each respective spinous process, as further shown in FIG.4C. As previously mentioned, providing an interspinous stabilizationdevice 22 that can be securely anchored to the lamina may be desirablesuch as where the spinous process is damaged, weakened, brittle orinsufficient in size to serve as a bearing surface.

In some embodiments, the lateral walls or plates 36 may be adjustablewith respect to the spacer body 22. For example, the lateral walls 36may be formed of a malleable material such that, after implantation, thesurgeon may compress the lateral walls 36 together to reduce the gapbetween the lateral walls 36, thereby securely fixing the spacer body 22to a spinous process located therein or an adjacent laminar surface. Inaddition, the lateral walls 36 may be spread apart to facilitateinsertion. The lateral walls 36 may be compressed or spread apart, forexample, using surgical pliers or forceps.

Each of the lateral walls or brackets 36 may include an aperture 42 forreceiving a fixation element, such as, a bone fastener to fix thebrackets 36 to the lamina. Such fastening elements can ensure that thebrackets 36 lie flat and/or securely against the lamina in order toallow rigid fixation to the vertebrae. The aperture 42 can encompass arange of sizes and shapes. For example, the aperture 42 may be formed asan elongated slot as shown in FIGS. 3 and 4A. The apertures 42 of theinferior and superior sections 32, 34 may be staggered along alongitudinal axis, further shown in FIG. 4A. This feature allows aplurality of the implantable devices 22 to be stacked, or implanted,along the spinal column. Also contemplated is the use of the systems ofthe present disclosure with other implantable interlaminar-interspinousdevices such as the ones described earlier. These other implantableinterlaminar-interspinous devices could be stacked on top or below thesystems presently described.

FIG. 3 illustrates one embodiment of the system 20 of the presentdisclosure in which a combination of dynamic stabilization and rigidstabilization can be achieved with the same device 22. In the systemshown in FIG. 3, a different pair of fixation elements, or bone screws50, 60 can be utilized. The pair of bone screws 50 extending through thetop plates by way of apertures 42 is shorter in length than the pair ofbone screws 60 extending through the bottom plates by way of apertures42. By using different lengths of screws, specifically translaminarscrews, the implantable device 22 of the system 20 allows a gradient offixation strength across the device 22. The top level of the device 22may allow some degree of movement, thereby creating a dynamicstabilization scheme. The bottom level of the device 22 may be morerigidly fixed as a result of the longer pair of translaminar screws 60being used, thereby forming a tighter, more secure connection with thelower vertebra. In contrast, the shorter pair of screws 50 applied atthe top level may sufficiently prevent the spacer body 22 from movingout of position, but may be sufficiently loose so as to allow a smallamount of micromotion between the spacer body 22 and spinous process orvertebra, so as not to promote fusion, or at least cause fusion to occurmore slowly.

When system 20 is configured to allow some dynamic motion, it iscontemplated that the apertures 42 of the implantable device 22,particularly at the level where the motion is to occur, would beconfigured to accommodate the movement of the screws 50. For instance,the apertures 42 may be elongated slots or other shapes to allow theheads of the screws to “rock” back and forth during motion. Further, insome embodiments, the system 20 can include only a single pair offixation elements. For example, two bone screws 60 may be used to secureeither the top or bottom level of the adjacent vertebrae. Thus, thespacer body 22 may be secured to one vertebra and not the other adjacentvertebra.

While FIGS. 3 and 4A-4C illustrate a system 20 in which a pair ofshorter screws 50 is used with the top level of the implantable device22, it is understood that the same system 20 could easily accommodatethe use of shorter screws 50 at the bottom level, while the longerscrews 60 could be used at the top level. In other words, the set ofscrews 50, 60 shown could be reversed, so that each set 50, 60 couldequally be used at either level of the device 22. In addition, thescrews 50, 60 may differ from one another in other manners, such asdiameter, thread pitch, etc. as well as length. Accordingly, a user maycustomize the system 20 in a number of ways depending on the particularneed of the patient.

FIG. 5 illustrates a system 20 in which the same or very similar pairsof screws 60 are used with the implantable device 22 at the top andbottom levels. That is, the screws 60 used at both levels have the samerelative strength. In this particular configuration, the system 20 mayserve to promote fusion of the relevant vertebrae. It is envisioned thata tight, secure connection between the spacer body 22 and adjacentvertebrae will limit movement at the selected vertebral level, therebypromoting fusion at that level.

In some embodiments, a stiffening plug or insert 70 may be used toprovide additional stiffness, particularly at the midsection 30. FIGS.6A-6B, 7A-7C and 8 illustrate the system 20 and implantable device 22 ofFIG. 5 whereby a stiffening insert 70 is placed inside the U-shapedmidsection 30 of the spacer body 22. The stiffening insert 70 may beformed as a material folded onto itself, as shown in FIGS. 6A-6B, 7B,and 7C. Alternatively, the stiffening insert 70 may be formed as aunitary body.

As shown, the insert 70 may be configured with an opening to receive afixation or attachment element 72, such as a screw, plug, rivet, spike,etc. The attachment element 72 may be configured for insertion through ahole 74 on the spacer body 22, as seen in FIG. 5. In one example, thehole 74 may be threaded and the attachment element 72 may includethreads at its terminal end, as shown in more detail in FIG. 7C. Theattachment element 72 may include a tool-engaging opening to facilitateinsertion with a tool (not shown), as illustrated in FIGS. 6A, 7A and7C. In addition, as shown in FIGS. 6A and 7A, the stiffening insert 70may be configured with a surface feature such as a protrusion orgeometric shape that complements a groove or slot within the spacer body22 for receiving the stiffening insert 70. In one embodiment, a dovetailconnection or other shape-fitting connection, for example, could beprovided between the stiffening insert 708 and the spacer body 22.

To further enhance the ability of the implantable device 22 to besecured to the surrounding bone and soft tissue, the implantable device20 may include a number of surface modifications. For example, thespacer body 22 may include surface alterations that may facilitatetissue attachment, bonding, or fixation. These surface alterations mayinclude teeth, barbs, beads, surface roughening, or the addition ofbioactive agents to one or more sections of the device 22. For example,the device 22 may include one or more teeth or barbs 40 for securing thedevice 22 to bone and/or soft tissue. As shown, the teeth 40 may belocated on the spacer body 22, such as on an outer surface of theinferior section 32 and/or superior section 34. Alternatively, or inaddition, the barbs 40 may be located on an inner surface of the lateralwalls 36. The barbs 40 may help the spacer body 22 securely engageconnective tissue or a bony surface of a vertebra, such as the spinousprocess of the vertebra.

Additionally, the implantable device 22 may also include roughened orporous surfaces, for example, to promote bony ingrowth. The roughened orporous surfaces may enhance attachment between implant surfaces andbone. In addition, some porous surfaces may facilitate tissue ingrowthto form a biological bond between sections of the device 22 and thesurrounding bone and/or soft tissue. Roughened or porous surfaces may beincluded on any portion of the device 22.

The surface of the device 22 may also include biologically activeagents. These agents may include osteogenic factors to furtherfacilitate bonding between components of the device 22 and thesurrounding bone and/or soft tissue. Further, the device 22 may includetherapeutic agents, such as antibiotics, steroids, anti-thromboticagents, anti-inflammatory drugs, and/or analgesic agents. In oneembodiment, the biologically active agent may be contained in a coatingon the device. Alternatively, or in addition, the device may be porous,and the biologically active agent may be contained in the pores of thedevice. The biologically active agent may be, for example, bonemorphogenic protein (BMP) for modulating cartilage or bone growth.

A number of biocompatible materials are suitable for forming the spacerbody 22 of the present disclosure. In one embodiment, the spacer body 22may be formed from a medical grade metal, such as titanium or a titaniumalloy. The spacer body 22 may also be formed from a variety of othermaterials, such as stainless steel, cobalt chrome, ceramics, and/orpolymeric materials, such as ultra-high molecular-weight polyethylene(UHMWPE) and polyetheretherketone (PEEK), either alone or in combinationwith other suitable materials.

Although the implantable device 22 is described and shown with superiorand inferior lateral walls 36, the device 22 can also comprise aU-shaped implant with a single pair of lateral walls 36. Such devicesmay be used at the L5-S1 vertebral level. For example, the device 22 mayinclude a single pair of lateral walls 36 configured to engage thespinous process and lamina of the L5 vertebra. Further, the device 22may include a mechanism for securing the inferior section 32 to thesacrum. As noted above, the superior lateral walls can be secured to theL5 spinous process with translaminar screws 60, thereby limitingmovement at the L5-S1 level and promoting fusion at that level.

FIGS. 9A-9B and 10A-10B illustrate additional exemplary embodiments ofimplantable devices of the present disclosure. FIGS. 9A and 9Billustrate one embodiment of an implantable device 122 for use in atranslaminar interspinous stabilization system 120 similar to the system20 previously described. The implantable device 122 shown in FIGS. 9Aand 9B shares similar features to the previously disclosed implantabledevice 22, whereby these like features or structures are indicated bythe same reference numerals used for implantable device 22, followingthe prefix “1”. However, in addition to having all of the features ofimplantable device 22, implantable device 122 of FIGS. 9A and 9B isprovided with additional portals or openings 180 for receiving orinserting a fusion promoting material, as well as for allowing bonyingrowth. The openings 180 may be located on the inferior and superiorsections 132, 134 and may be configured as one or more circles, slots,squares, rectangles, etc. For example, FIGS. 9A and 9B illustrate anembodiment in which an opening 180 is provided on each of the inferiorand superior sections 132, 134 of the implantable device 122.

FIGS. 10A and 10B, on the other hand, illustrate an embodiment in whichmore than one opening 180 a, 180 b is provided on each of the inferiorand superior sections 132, 134 of the implantable device 122. As furthershown in FIG. 10A, the size and shape of the openings 180 a, 180 b maydiffer from section to section. In one embodiment, opening 180 a may besmaller than opening 180 b. The openings 180 a, 180 b may allow accessreceive a fusion promoting material, such as a bone substitute material,an allograft or autograft material, or other graft material effective toenhance bone growth and fusion. Additionally, the openings 180 may serveas portals for bony ingrowth.

As shown and described, the present disclosure provides interspinousstabilization systems that can be configured to provide either dynamicor rigid stability to the affected vertebral segment of the spinalcolumn. For instance, the system may allow dynamic stability forcontrolled motion of the adjacent vertebrae being affected. Onecontemplated manner of achieving this is by adjusting or varying thetype of translaminar screw being used. However, as further shown anddescribed, the same system may also be easily converted or adapted toallow for rigid, fusion-promoting securement, if so desired or needed.This can be achieved through the manner of fixation, such as with thetype of translaminar screw being used or the number of screws beingused. Another manner of promoting fusion with the same system is withthe use of a stiffening insert or plug, or fusion promoting materialsuch as bone graft material or other bone growth inducing material.

FIGS. 11A, 11B and 12 describe still another exemplary embodiment of atranslaminar interspinous stabilization system 220 of the presentdisclosure. FIGS. 11A and 11B illustrate one embodiment of animplantable device 222 for use in a translaminar interspinousstabilization system 220 similar to the system 20 previously described.The implantable device 222 shown in FIGS. 11A and 11B shares similarfeatures to the previously disclosed implantable device 22, wherebythese like features or structures are indicated by the same referencenumerals used for implantable device 22, following the prefix “2”.However, in addition to having all of the features of implantable device22, implantable device 222 of FIGS. 11A and 11B may further containopenings for receiving a fixation element such as a rivet, bolt and nut,or other similar fastener 290. The location of the opening for thefastener 290, and the fastener itself, may be configured so as to allowfixation through a spinous process, thereby securing the lateral walls236 of the implantable device 222 to the spinous process. As shown, thedevice 222 may be configured to receive the fastener 290 at either ofthe top or bottom levels. In one embodiment, the fastener 290, as wellas the manner of receiving the fastener 290 within the implantabledevice 222 and its assembly, may be similar in respect to the onedisclosed in U.S. Pat. No. 7,922,750 entitled “Interlaminar-InterspinousVertebral Stabilization System.”

As shown in FIGS. 11A and 11B, the system 220 may comprise animplantable device 222 that can accommodate a fastener 290 at both thetop and bottom levels through the upper and lower lateral walls 236. Inaddition, the implantable device 222 may also allow for a pair oftranslaminar screws 260 to be used at the top level, as shown in FIG.12. It is, of course, understood that the system 220 may easily beconfigured to allow translaminar screws 260 to be used at both the topand bottom levels, as previously described and shown, for even greateranchorage. By securely attaching the implantable device 222 to thevertebra, the system 220 of the present disclosure provides afusion-promoting system for vertebral stabilization.

The systems 20, 120, 220 of the present disclosure allow the user greatflexibility in adapting the systems to the current needs of the patient.As already mentioned, the systems can provide the option of eitherdynamic or rigid stability. The systems can also be adapted fordifferent uses over time. For example, a clinician may initially use oneof the systems for dynamic stability, and then over time as thepatient's needs changes, the clinician can modify the existing implantedsystem to allow for more rigid stability, such as by inserting astiffening plug into the device, or inserting some bone growth promotingmaterial, or even inserting translaminar screws or a fastener to theimplantable device where one was not already present. Thus, the dynamicstability of the initial system can be converted into a rigidly stablesystem without great effort.

It is contemplated that multiple systems 20, 120, 220 of the presentdisclosure may be used together for multi-level vertebral stabilization.These systems may be identical, or they may be different, and can beused at the same time or over time with the patient's changing needs.For example, system 20 may be used at one level while system 220 is usedat a different level, either at the same time or at different times suchas where system 220 is implanted after system 20 has already beenimplanted. Likewise, each of these systems 20, 120, 220 may be used withother implantable interspinous devices, such as those currentlyavailable and previously mentioned, thereby allowing ultimateflexibility and variability in terms of the combination of devices thatcan be used to address the patient's particular needs.

Other embodiments of the invention will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritof the invention being indicated by the following claims.

1. A translaminar, interspinous stabilization system comprising: animplantable device for placement between two adjacent vertebrae, thedevice comprising an inferior section, a superior section, a flexiblemidsection extending therebetween, a first pair of lateral platesextending from the inferior section, and second pair of lateral platesextending from the superior section, each of the lateral platesincluding an aperture for receiving a bone fastener therethrough andbeing configured to engage a laminar surface of one of the vertebrae; afirst bone fastener for placement through one of the first pair oflateral plates; and a second bone fastener for placement through one ofthe second pair of lateral plates, each fastener securing the device tothe laminar surface of one of the vertebra.
 2. The system of claim 1,wherein the inferior section, superior section and flexible midsectiontogether form a U-shaped body.
 3. The system of claim 2, wherein theflexible midsection is configured to seat against the lamina between theadjacent vertebrae.
 4. The system of claim 1, wherein the lateral platesare contoured to match the anatomic shape of the laminar surface.
 5. Thesystem of claim 1, wherein the bone fastener comprises a bone screw. 6.The system of claim 1, wherein each aperture of the lateral platescomprises an elongated slot.
 7. The system of claim 1, wherein thelength of the first bone fastener is the same as the length of thesecond bone fastener.
 8. The system of claims 1, wherein the length ofthe first bone fastener is different than the length of the second bonefastener.
 9. The system of claim 1, further including an insert forplacement within the flexible midsection.
 10. The system of claim 1,wherein at least one of the inferior and superior sections includes anopening for insertion of material or for accommodating bone growththerethrough.
 11. The system of claim 10, further including a fusionpromoting material for placement within the flexible midsection throughthe opening.
 12. The system of claim 11, wherein the fusion promotingmaterial comprises allograft, autograft, or bone substitute material.13. A translaminar, interspinous stabilization system comprising: animplantable device for placement between two adjacent vertebrae, thedevice comprising an inferior section, a superior section, a flexiblemidsection extending therebetween, and a pair of lateral plates forengaging a laminar surface of one of the vertebra, each of the lateralplates including an aperture for receiving a bone screw therethrough;and at least one screw for placement through at least one lateral platefor securing the device to the laminar surface of one of the vertebra.14. The system of claim 13, wherein the inferior section, superiorsection and flexible midsection together form a U-shaped body.
 15. Thesystem of claim 14, wherein the flexible midsection is configured toseat against the lamina between the adjacent vertebrae.
 16. The systemof claim 13, wherein the flexible midsection is compressible andextendable.
 17. The system of claim 13, wherein the pair of lateralplates extends from one of the superior or inferior sections.
 18. Thesystem of claim 17, wherein the pair of lateral plates further includesan opening for receiving a fastener therethrough, the opening beingconfigured to allow the fastener to secure the lateral plates against aspinous process.
 19. The system of claim 13, further comprising a secondpair of lateral plates extending from one of the superior or inferiorsections, each of the lateral plates of the second pair including anaperture for receiving a bone fastener; and a second bone fastener forplacement through at least one of the second pair of lateral plates. 20.The system of claim 13, wherein the pair of lateral plates are contouredto match the anatomic shape of the laminar surface.
 21. The system ofclaim 13, wherein the aperture of the lateral plates comprises anelongated slot.
 22. The system of claim 19, wherein the length of thefirst bone fastener is the same as the length of the second bonefastener.
 23. The system of claims 19, wherein the length of the firstbone fastener is different than the length of the second bone fastener.24. The system of claim 13, further including an insert for placementwithin the flexible midsection.
 25. The system of claim 1, wherein atleast one of the inferior and superior sections includes an opening forinsertion of material or for accommodating bone growth therethrough. 26.The system of claim 25, further including a fusion promoting materialfor placement within the flexible midsection through the opening. 27.The system of claim 26, wherein the fusion promoting material comprisesallograft, autograft, or bone substitute material.
 28. A method ofsegmentally stabilizing a spine, comprising: selecting a vertebral levelto be treated; and positioning an implantable device between twoadjacent spinous processes of two vertebrae of the selected vertebrallevel, wherein the implantable device comprises an inferior section, asuperior section, a flexible midsection extending therebetween andconfigured to seat against the lamina between the adjacent vertebrae,and a pair of lateral plates for engaging a laminar surface of one ofthe vertebra, each of the lateral plates including an aperture forreceiving a bone screw therethrough and being configured to engage alaminar surface of one of the vertebrae.
 29. The method of claim 28,further including placing a first bone fastener translaminarly throughan aperture of the pair of lateral plates, the fastener securing thedevice to the laminar surface of one of the vertebra.
 30. The method ofclaim 28, wherein the implantable device further comprises a second pairof lateral plates for engaging a laminar surface of one of the vertebra,the second pair of lateral plates including an aperture for receiving abone screw therethrough and being configured to engage a laminar surfaceof one of the vertebrae, and further including placing a second bonefastener through one of the second pair of lateral plates and securingthe device to the laminar surface of another one of the vertebra. 31.The method of claim 30, wherein the length of the first bone fastener isthe same as the length of the second bone fastener.
 32. The method ofclaims 30, wherein the length of the first bone fastener is the same asthe length of the second bone fastener.
 33. The method of claim 28,further including inserting a stiffening plug into the flexiblemidsection of the implantable device.
 34. The method of claim 28,wherein at least one of the inferior and superior sections includes anopening for insertion of material or for accommodating bone growththerethrough, and further including placing a fusion promoting materialwithin the flexible midsection through the opening.
 35. The method ofclaim 28, wherein the pair of lateral plates includes an opening forreceiving a fastener, and further including inserting a fastener throughthe opening of the pair of lateral plates, the opening being configuredto allow the fastener to secure the lateral plates to a spinous process.36. The method of claim 28, further including: selecting a differentvertebral level to be treated; positioning another implantable devicebetween two adjacent spinous processes of two vertebrae of the differentvertebral level selected; and securing the other implantable device. 37.The method of claim 36, wherein the implantable devices are the same atthe different vertebral levels.
 38. The method of claim 36, wherein theimplantable devices are different at the different vertebral levels.